本课的代码：
(setq ss (ssget '((0 . "TEXT")))
i 0
)
(repeat (sslength ss)
(setq ent (ssname ss i))
(setq ents (entget ent))
(setq told (assoc 1 ents))
(setq tnew (cons 1 (rtos (* 2.204623 (atof (cdr told))) 2 1)))
(setq ents (subst tnew told ents))
(entmod ents)
(setq i (1+ i))
)
